Undead Geonosians in the catacombs
Beneath the surface of Geonosis lay a sprawling network of tunnels known by various names: the Geonosian catacombs, the Geonosis caves, or the Catacombs of Geonosis. These extensive tunnel systems were situated under every Geonosian structure.
During the events of the Second Battle of Geonosis, Jedi Order Padawans, specifically Barriss Offee and Ahsoka Tano, navigated these catacombs in an attempt to reach the reactor powering the Geonosis primary droid foundry. Later, Galactic Republic forces journeyed through the tunnels located beneath the Progate Temple, where the Jedi and clone troopers encountered Karina the Great, who was the queen of the Geonosians.